JP4281680B2 - Optical disk device - Google Patents

Description

  The present invention relates to an optical disc apparatus, and more particularly to a management technique for a buffer memory for storing data to be recorded and data to be reproduced.

  Among disk devices widely used as auxiliary storage devices for computers, fixed magnetic disk devices (HDDs) and optical disk devices other than flexible magnetic disk devices (FDDs) realize high-speed and large-capacity data recording and reproduction. Therefore, a microcomputer is built in.

  Since the optical head and the head carriage are heavier than an HDD, the response performance of random access is inevitably inferior. For this reason, when data is recorded in the optical disk device, data accompanying a data recording command (hereinafter referred to as “write command”) issued from the host device is received by the buffer memory, and when the reception is completed, the recording completion is immediately sent to the host device. By reporting, the apparent data recording speed seen from the above apparatus is improved. Data associated with a normal write command is configured to be written to an actual optical disk when there is no free space in the buffer memory and cannot be received, or after a certain time has elapsed since the most recent write command. This is generally called “delayed writing” and is well known. Delayed writing is realized by the firmware of the microcomputer, and the performance (response performance) of the disk device viewed from the host varies greatly depending on the processing method.

  The write commands issued from the host device include a normal write command and a write command with “FUA bit” added. Data accompanying a write command to which this bit, which is an abbreviation of “Force Unit Access”, is not subject to delayed writing, and the received data is recorded as soon as the accumulation in the buffer memory is completed. In many cases, this command is mainly applied to data such as directory information of an OS file system that is damaged if recording fails.

  When recording data in a sector-formatted optical disk device such as a DVD-RAM, the write data accompanying the write command coming from the device (host) is received by the buffer memory, and not actually recorded on the optical disk. When the reception to the buffer memory is completed, the completion of the command is reported to the host. That is, the delayed writing is performed. The unrecorded data stored in the buffer memory starts actual recording on the optical disc at the following timing.

(1) Sequential write If the logical address (LBA) of the write data associated with the write command coming from the host is continuous, it is determined that continuous recording is performed without the seek operation of the optical pickup. , Keep receiving until the buffer is full. Recording on the optical disk (hereinafter “actual recording”) is started when the buffer becomes full or when no command is received from the host for a certain period of time from the most recent write command.

(2) Random write When the logical address (LBA) of the write data associated with the write command that continues from the host is discontinuous, the physical address on the optical disc that requires the seek operation of the optical pickup is discontinuous It is determined that the recording operation is to be performed, and a counter indicating the number of data with discontinuous logical addresses is incremented by +1. The counter is incremented each time discontinuous write data comes, and when the counter reaches a predetermined value, for example, 10, actual recording is started even if the buffer is not full (pseudo buffer size is reduced). This is because the seek operation is a process that takes a very long time, tends to cause the host to wait, and possibly a timeout error is output from the host. Of course, as in the case of the sequential write, even if the counter does not reach the predetermined value, the actual recording is started when a predetermined time elapses from the most recent command.

  Patent Document 1 shown below discloses a method of using a buffer memory.

JP 2000-339856 A

  Conventionally, in both cases (1) and (2), once actual recording has occurred on the disk, a read / write command is received from the host until all the unrecorded data in the buffer memory has been recorded. Could not respond immediately.

  As described above, in the case of a random write, a time-out to the host can be prevented by providing a limitation by a discontinuous counter and reducing the size of the buffer memory in a pseudo manner. However, in the case of sequential write, the maximum size of the buffer memory is used, so high-speed writing can be expected. However, when replacement processing occurs, the recording execution time increases and response performance deteriorates rapidly. . This deterioration in response performance is proportional to the size of the buffer memory. In the worst case, the host determines that a timeout has occurred, and the host resets the bus. Even if the size of the buffer memory is increased to improve the corner response performance, this has an adverse effect due to the occurrence of the replacement process. The occurrence of the bus reset means that the recording is interrupted from the host, and the reliability of the user with respect to the optical disk device may be impaired.

  An object of the present invention is to provide a highly reliable optical disc apparatus that does not receive a timeout from a host even if the buffer memory is increased.

  As a basic technical idea for solving the above problem, even if unrecorded data remains in the buffer memory, if a read command is received from the above device, the write operation can be interrupted at an appropriate timing. It was configured to allow processing. Here, the interruption during the write operation is a timing that causes a discrete movement of the optical pickup with respect to the physical address of the optical disc, such as a lens kick or a thread seek, and a free area (reproduction) larger than the capacity required by the read command in the buffer memory This means that when a data storage area) occurs, the seek operation for the next write is stopped and the read command is processed.

  Here, in order to more efficiently perform the write interruption and accompanying read processing, if a minimum readable area is secured in the buffer memory in advance, the read processing is executed immediately after the seek operation is stopped. it can.

  Furthermore, when a free capacity (reproduction data storage area) exceeding the capacity required for the read command processing is obtained at the time of the write interruption, the pre-reading is performed beyond the address specified by the read command, so that the host device Responsiveness to can be expected.

  According to the present invention, even in the case of sequential write, even when a read command comes after the write command, data can be read from the optical disc immediately in response to the read command, and a situation where the host device determines that a timeout has occurred. Can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an overall configuration diagram of an optical disc apparatus according to the present embodiment. A rewritable optical disk 10 such as a DVD-RAM is rotationally driven by a spindle motor (SPM) 12. The spindle motor SPM 12 is driven by a driver 14, and the driver 14 is servo-controlled by a servo processor 30 so as to have a desired rotation speed.

  The optical pickup 16 includes a laser diode (LD) for irradiating the optical disk 10 with laser light and a photodetector (PD) that receives reflected light from the optical disk 10 and converts it into an electrical signal, and is disposed opposite to the optical disk 10. . The optical pickup 16 is driven in the radial direction of the optical disk 10 by a thread motor 18, and the thread motor 18 is driven by a driver 20. The driver 20 is servo-controlled by the servo processor 30 similarly to the driver 14. The LD of the optical pickup 16 is driven by a driver 22, and the driver 22 is controlled by an auto power control circuit (APC) 24 so that the drive current becomes a desired value. The APC 24 controls the drive current of the driver 22 so that the optimum recording power selected by OPC (Optimum Power Control) executed in the test area (PCA) of the optical disc 10 is obtained. The OPC is a process of recording test data on the PCA of the optical disc 10 by changing the recording power in a plurality of stages, reproducing the test data, evaluating the signal quality, and selecting a recording power that can obtain a desired signal quality. It is. For the signal quality, β value, γ value, modulation factor, jitter, etc. are used.

  When data recorded on the optical disk 10 is reproduced, a laser beam of reproduction power is irradiated from the LD of the optical pickup 16, and the reflected light is converted into an electric signal by the PD and output. A reproduction signal from the optical pickup 16 is supplied to the RF circuit 26. The RF circuit 26 generates a focus error signal and a tracking error signal from the reproduction signal and supplies them to the servo processor 30. The servo processor 30 servo-controls the optical pickup 16 based on these error signals, and maintains the optical pickup 16 in an on-focus state and an on-track state. Further, the RF circuit 26 supplies an address signal included in the reproduction signal to the address decoding circuit 28. The address decoding circuit 28 demodulates the address data of the optical disk 10 from the address signal and supplies it to the servo processor 30 and the system controller 32. In the case of a DVD-RAM, address data can be obtained by a CAPA (Complimentary Allocated Pit Addressing) method, and the address data present in the header portion recorded in the sector is reproduced. Further, the RF circuit 26 supplies the reproduction RF signal to the binarization circuit 34. The binarization circuit 34 binarizes the reproduction signal and supplies the obtained 8-16 modulation signal to the encoding / decoding circuit 36. In the encode / decode circuit 36, the binarized signal is demodulated and error-corrected by 8-16 to obtain reproduction data, and the reproduction data is output to a host device such as a personal computer via the interface I / F 40. When the reproduction data is output to the host device, the encoding / decoding circuit 36 temporarily stores the reproduction data in the buffer memory 38 and outputs it.

  When recording data on the optical disk 10, data to be recorded from the host device is supplied to the encode / decode circuit 36 via the interface I / F 40. The encode / decode circuit 36 stores data to be recorded in the buffer memory 38, encodes the data to be recorded, and supplies the data to the write strategy circuit 42 as 8-16 modulation data. The write strategy circuit 42 converts the EFM data into a multi-pulse (pulse train) according to a predetermined recording strategy and supplies it to the driver 22 as recording data. The recording strategy is composed of, for example, the pulse width of the first pulse, the pulse width of the subsequent pulse, and the pulse duty in the multi-pulse. Since the recording strategy affects the recording quality, it is usually fixed to a certain optimum strategy. A recording strategy may be set at the time of OPC. The laser light whose power is modulated by the recording data is irradiated from the LD of the optical pickup 16 and the data is recorded on the optical disk 10. After recording the data, the optical pickup 16 reproduces the recorded data by irradiating a laser beam with a reproduction power, and supplies it to the RF circuit 26. The RF circuit 26 supplies the reproduction signal to the binarization circuit 34, and the binarized 8-16 modulated data is supplied to the encode / decode circuit 36. The encode / decode circuit 36 decodes the 8-16 modulation data, and performs a replacement process when the data cannot be normally decoded. Specifically, the recorded data stored in the buffer memory 38 is recorded in the replacement area.

  Since DVD-RAM and the like have a sector format and record data in units of 1 ECC block (16 sectors), the buffer memory 38 must store recording data for 16 sectors. Therefore, when data is recorded and it is less than one ECC block, it is necessary to satisfy this by some method to make data for one ECC block. There are several methods for setting data for one ECC block, but the first method is to access the address of the optical disk 10 corresponding to the address of the empty area that is less than one ECC block of the buffer memory, and the data existing at the corresponding address. Is used to fill the buffer memory. In the second method, in the case of sequential write in which the end logical address of stored data in the buffer memory and the start logical address of data scheduled to be supplied from an external device are consecutive, data corresponding to the free capacity is used. Is requested to the host device, and the data supplied from the host device in response to the request is stored in the free space to fill the free space at the end (the free space at the start is the same as in the first method). Any method may be used.

  In the optical disc apparatus 1 according to the present embodiment, the system controller 32 controls the buffer memory 38 to perform well-known delayed writing on the optical disc 10. In addition, data read from the optical disk 10 is appropriately stored to help reduce the number of random accesses to the disk. The optical disk apparatus 1 of the present embodiment has a larger capacity of the buffer memory 38 (for example, 4 MB) than the conventional optical disk apparatus 1, and can efficiently receive large-capacity sequential write data with continuous LBA. However, as is well known, optical disks are vulnerable to dust and dirt, and data recording cannot always be accomplished with stable quality. For this reason, the DVD-RAM has spare areas on the inner and outer peripheral sides of the disk. If a write error occurs at a specific location in the recording area during the data recording process on the optical disc 10, a replacement process must be performed to compensate for this, so the data in the area where recording failed Is recorded in the replacement area. At this time, the optical pickup 16 is accompanied by a seek from the track on which recording has been performed to the replacement area. With the seek, the time required for data recording increases extremely. That is, when the capacity of the buffer memory 38 is increased, if a replacement process occurs during a sequential write after a write command is accepted from the host, even if a read command is issued from the host, it cannot be executed immediately, and a bus due to timeout There is a high possibility of receiving a reset.

  Therefore, when the system controller 32 receives a read command from the host while the write data stored in the buffer memory 38 is actually being recorded on the optical disc 10, it sets a flag indicating that the read command has come. To do. When the currently executing write process is completed, it is determined whether or not the flag is set. If the flag is set, the write process scheduled to be executed next is temporarily suspended and used in the buffer memory 38. Check the condition. Of the write data existing in the buffer memory 38, data that has already been recorded on the optical disc 10 (recorded data), and recording has not yet been completed, so it is necessary to store the data in the buffer memory 38. Data (unrecorded data) is determined, and it is determined whether or not a read command can be executed in the recorded data area remaining in the buffer memory 38. Since recording on the optical disk 10 is performed in units of 1 ECC block as described above, recorded data is also determined in units of 1 ECC block. As a result of the discrimination processing, when it is determined that there is a recorded data area exceeding the capacity specified by the read command, it is decided to divert this recorded data area to the read data storage area. Then, a predetermined reproduction operation is executed according to the received read command. In this way, the recorded data area is diverted to the read data storage area, and the current data recording operation is interrupted when random access occurs, enabling quick execution of read commands and preventing timeouts. To do.

  When there is no recorded data area exceeding the capacity specified by the read command when the read command is received, the write process to be executed next is completed, the buffer memory 38 is verified again, and the read command is used. Write processing is executed until a recorded data area exceeding the specified capacity is generated. If a recorded data area of a predetermined capacity or more can be secured, the read process is executed prior to the next write process to be executed.

  When the read process is completed, the host waits for the next command until a predetermined time elapses. Even if the read command continues, the command is received from the host and executed as long as the capacity of the recorded data area existing in the buffer memory 38 permits. If no command is received after a predetermined time has elapsed, the interrupted data recording operation is resumed.

  2 and 3 show processing flowcharts of the present embodiment. The system controller 32 determines whether the command received from the host device is a write command (S101). If it is a write command, the write data accompanying the write command is received and stored in the buffer memory 38 (S102). The storage in the buffer memory 38 is executed until the buffer memory 38 becomes full (FULL) (S103). Here, the FULL state of the buffer memory 38 means a state in which there is no free space for storing all the write data from the host device. The system controller 32 calculates the total capacity of data to be recorded from the start logical address and the end logical address of the write data, and verifies whether or not the capacity can be accommodated in the free area of the buffer memory 38 to determine whether or not it is FULL. Determine. This write data storage processing is executed until the empty area of the buffer memory 38 is filled (used up) if the logical address of the continuous write data is continuous, but the logical address of the continuous write data If the number is not continuous, the counter for counting discontinuous data is incremented, and if the number exceeds a certain value, reception is aborted even if all free areas of the buffer memory 38 are not filled (even if they are not used up). . This is a restriction process performed in order to prevent the host device from waiting more than necessary due to a decrease in the access speed accompanying thread seek, and not to cause a timeout.

  When it is determined that the buffer memory 38 is in the FULL state, processing is performed to convert the logical address of the write data (unrecorded data) stored in the buffer memory 38 into a physical address on the optical disc 10 (S104). This is because the recording operation on the optical disc 10 of the optical disc apparatus 1 is finally configured to perform a single write process on a section where the physical addresses of the optical disc 10 are continuous. . That is, a single write process is a process that is completed by itself and cannot be interrupted. Therefore, even if data is continuous in the logical address, it may become discontinuous due to replacement processing or the like when converted to a physical address. Therefore, logical-physical address conversion processing is performed prior to write processing, and then the order of write processing is determined in order of physical addresses for unrecorded data in the buffer. Next, a write operation for recording the unrecorded data on the optical disc 10 is started (S105). The write operation includes a process of filling up an empty area that is less than one ECC block as described above. After write data having consecutive physical addresses in units of one ECC block is formed, these are sequentially read from the buffer memory 38, encoded, supplied to the optical pickup 16, and recorded on the optical disc 10. When the data recording (write operation) is completed, the same physical address is reproduced again and the signal quality is verified (verify) after setting the reproduction conditions slightly stricter than those during normal reproduction. If a read error occurs and decoding cannot be performed normally, the data is recorded alternately in the replacement area.

  The system controller 32 determines whether or not a read command is received from the host device during the write operation (S106). If the read command has not been received, the write operation is continued and repeated until all the write data stored in the buffer memory 38 is recorded on the optical disc 10 (S108, S110). On the other hand, when a read command is received, a flag indicating that the read command has been received is set (S107), and at a timing when the current write operation can be interrupted (S108), it is determined whether or not the flag is set. Verification is performed (S109). If the flag is set, the received read command is executed to shift to the following process to prevent timeout.

  FIG. 3 shows processing when a read command is received and the write operation is interrupted. First, the system controller 32 determines whether or not there is a free area (recorded data area) that can respond to a read command request in the buffer memory 38 (S202). Most of the buffer memory 38 is occupied by unrecorded data (completing recording means not only recording on the optical disc 10 but also verifying thereof), and only responding to a read command request. If there is no free area, the read command cannot be executed, so the process returns to S110, and the write process in S105 is continued again to create a free area. Here, the free area is an area where there is no unrecorded data in the buffer memory 38 immediately after the apparatus is started, or it is not necessary to store the data in the buffer memory 38 after recording on the optical disk 10 is completed. It means the area of recorded data.

  On the other hand, if there is a free area in the buffer memory 38 that can respond to the read command request, the read data read from the optical disk 10 can be stored. Therefore, the system controller 32 checks whether or not the data requested by the read command already exists in the buffer memory 38 (S203). If the data has already been read and exists in the buffer memory 38, If the unrecorded data staying at 38 corresponds to that (data hit or cache hit), the data is transferred to the host device as it is (S208). As a result, the processing of the read command is completed, and the set flag is released (S209). If there is no data hit, it is necessary to read from the optical disc 10, but it is expected that the read command will be issued continuously from the host device, not just the address requested by the read command. By prefetching the data at the address following the requested data in advance, the cache hit rate in the next read command can be improved. If the read command continues, it is not preferable to keep the unrecorded data in the buffer memory 38 indefinitely. The unrecorded data will be disposed at the earliest possible time and will continue from the host device. We want to free up buffer memory 38 so that it can handle read commands to the maximum extent. Therefore, the recording process of unrecorded data is completed one by one, the process of the unrecorded data area is advanced, and a recorded data area (empty data area) is further secured. Note that the recording process in S204 is a write process that continues at a physical address, and if it is interrupted immediately before verification, an incomplete verification process is given priority over other write processes. Next, it is determined whether unrecorded data still exists (S205). If unrecorded data no longer exists, the entire area of the buffer memory 38 can be used as a read data storage area. If unrecorded data exists, the read data in the buffer memory 38 can be stored. After searching for a buffer area (S206), data (requested data + prefetched data) is read from the optical disk 10 and stored in the searched area (S207). After the read data is stored in the buffer memory 38, it is transferred from the buffer memory 38 to the host device (S208), the flag is cleared (S209), and the read process is completed. The read data storage area can be diverted to an area for storing new read data in the same manner as the recorded data area. That is, when no data hit occurs in S203 when a read command is received, the read data storage area is also used for the read process and the prefetch process together with the recorded data area.

  After the continuous write operation is interrupted as described above and the read command is executed, the process returns to the execution of the write command again. Then, when all of the recording of the remaining write data is completed, the process is terminated (S109, S110).

  4 to 7 schematically show the state of the buffer memory 38 at each stage of the processing described above. The capacity of the buffer memory 38 is arbitrary, but in the figure, for the convenience of explanation, it is assumed that the capacity can store data for 6 ECC blocks.

  FIG. 4 shows a state in which it is determined as FULL after storing write data with continuous logical addresses supplied from the host device, and a state in which YES is determined in S103 of FIG. If the first data area to the sixth data area (the capacity of each data area is one ECC block) from the top, write data is stored in all the data areas, and recording to the optical disc 10 has not yet been completed. It is in the “record” state. FIG. 5 shows a state in which logical / physical address conversion processing is performed from the state of FIG. 4, unrecorded data is divided in units of physical addresses, and the order of recording processing is given according to physical addresses. In FIG. 5, “unrecorded 1” consisting of data with continuous physical addresses for 2 ECC blocks from the top, “unrecorded 3” consisting of data with continuous physical addresses for 1 ECC block, and physical addresses for 1 ECC block are continuous. "Unrecorded 2" consisting of data to be stored, and "Unrecorded 4" consisting of data with continuous physical addresses for 2 ECC blocks are stored. Recording processing is performed in the order of unrecorded 2, unrecorded 3, and unrecorded 4 in the order of physical addresses from unrecorded 1. As illustrated in FIG. 5, in the actual data recording process on the optical disc 10, when a replacement process occurs, the logical address is continuous but the physical address is discontinuous. The order may change.

  In FIG. 6, data recording is sequentially performed on the optical disc 10 in units of ECC blocks continuous with physical addresses, and “unrecorded 1” and “unrecorded 2” in the buffer memory 38 are already recorded. State. At this point, S105 in FIG. 2 is in a state of being executed twice. “Unrecorded 1” and “Unrecorded 2” in which unrecorded data was stored have been recorded (recorded on the optical disc 10 and verification has been completed), and “recorded 1” and “recorded 2” have been recorded. Is in the state of "." The recorded data area is in a state where it is not necessary to actively store data and can be overwritten, that is, in an empty state.

  FIG. 7 shows that a read command is issued from the host device (S106), a flag is set (S107), write processing is interrupted (S108, S109), and unrecorded data is recorded as much as possible before executing the read command processing. Is a state in which a part of unrecorded data is recorded in order to secure a pre-read data area and after S204 in FIG. 3 is executed. Even in the state shown in FIG. 6, there is a free capacity (“recorded 1”, “recorded 2”) in response to the read command request, but only the data requested by the read command is “recorded 1”, for example. In this case, the efficiency decreases because it is necessary to read from the optical disk 10 each time the read command is continued. In addition, it is not good for the efficiency of read processing to keep unrecorded data indefinitely when read commands are continuous, but it also causes fatal data destruction in the event of an unexpected accident such as power interruption. It might be. Unrecorded data must be processed as quickly as possible. Therefore, as shown in FIG. 7, unrecorded data of “unrecorded 3” is recorded on the optical disc 10, and a free area is secured as “recorded 3”. As a result, not only the data requested by the read command but also the subsequent data can be pre-read and stored in “recorded 2” and “recorded 3”, and an improvement in reading speed due to a data hit can be expected. . Further, when the read command continues and no data hits in the buffer memory 38 (S203 in FIG. 3), the unrecorded data is gradually recorded (S204) before the read command processing, so as early as possible. Can process unrecorded data. In FIG. 7, the state has changed from “unrecorded 3” to “recorded 3”, so that it happens to be “recorded 1”, “recorded 2”, “recorded 3”, and 4 ECC blocks. Note that although there are minutes of recorded areas, the use of the recorded areas in the buffer memory 38 does not necessarily have a continuous address arrangement.

  FIG. 8 shows a state in which the data read from the optical disk 10 is stored in the buffer memory 38 after executing a write operation of a part of the unrecorded data to further secure a free space, and after executing S207 in FIG. It is a state. “Recorded 1” stores the data requested by the read command for 2 ECC blocks, and “recorded 2” and “recorded 3” store the pre-read data for 2 ECC blocks. The data stored in “recorded 1” is then transferred to the host device (S208 in FIG. 3). When a write command is issued again from the host device, the remaining “unrecorded 4” recording is completed, and from the state where there is no unrecorded data in the buffer memory 38 (S110), data reception is started again (S101, S101). S102).

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various change is possible.

  For example, in the present embodiment, the system controller 32 controls writing and reading to and from the buffer memory 38, but it goes without saying that the system controller 32 may be controlled by a memory controller different from the system controller 32.

  In this embodiment, in order to improve the probability of a data hit (cache hit), an area for storing a part of the pre-read data by recording a part of the remaining write data on the optical disc 10 before executing the read command is secured. However, the data read process may be performed without executing the process of S204. In this case, the capacity of the already existing free area is confirmed, and if the amount of data requested by the read command is smaller than this free capacity, only the data corresponding to the difference is prefetched and stored in the buffer memory 38. To do.

  Further, in the present embodiment, the buffer memory 38 is basically not logically divided into an area for storing write data and an area for storing read data read from the optical disk 10, but the buffer memory 38 is similar to the conventional technique. A part of 38 can be allocated to a dedicated area for read data. In this case, since there is always a storage area for read data, it is not necessary to determine whether or not there is an empty buffer in S202.

1 is an overall configuration diagram of an optical disc device according to an embodiment. It is a processing flowchart (the 1) of an embodiment. It is a processing flowchart (the 2) of an embodiment. It is a state explanatory view of the buffer memory. It is another state explanatory drawing of a buffer memory. It is another state explanatory drawing of a buffer memory. It is another state explanatory drawing of a buffer memory. It is another state explanatory drawing of a buffer memory.

Explanation of symbols

  10 optical disk, 16 optical pickup, 32 system controller, 38 buffer memory.

Claims (3)

An optical disc apparatus having a buffer memory for storing data to be recorded on an optical disc and storing data read from the optical disc,
According to the write command from the external device, when the read data is received from the external device after receiving the write data having continuous logical addresses in the buffer memory to the full state, the data stored in the buffer memory Determining means for determining whether or not there is a free data area including at least a recorded data area in response to the data amount requested by the read command;
When it is determined by the determination means that there is an empty data area corresponding to the amount of data requested by the read command, the optical data corresponding to the physical address of the optical disk is processed during the process of recording the write data in the order of the physical address of the optical disk. Control means for interrupting the recording process at the timing of causing a discrete movement of the pickup , reading data from the optical disc in response to the read command, and storing the read data in the empty data area;
An optical disc apparatus comprising: The apparatus of claim 1.
The control means increases the empty data area by executing recording on the optical disk for a part of the data area that has not been recorded on the optical disk, and reads the read data into the increased empty data area. An optical disc apparatus characterized by storing data read from the optical disc in response to a command and pre-read data following the data. An optical disc apparatus having a buffer memory for storing data to be recorded on an optical disc and storing data read from the optical disc,
The buffer memory is provided with a read data dedicated area for storing data read from the optical disc,
According to a write command from an external device, the write data is recorded in the physical address order of the optical disk when the read data is received from the external device after the write data having continuous logical addresses is received to the buffer memory to the full state. The recording process is interrupted at a timing that causes a discrete movement of the optical pickup with respect to the physical address of the optical disk, and data is read from the optical disk in response to the read command. Control means for storing data in a free data area including the read data dedicated area and at least a recorded data area;
An optical disc apparatus comprising:

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